first row in a group? in the report? in a crosstab? something else?

right click on the field
select format field
select number tab
select customize
select currency symbol
use a formula for 'enable currency symbol'

if recordnumber = 1 then crFloatingCurrencySymbol else crNoCurrencySymbol

set up the rest of your preferences on the Number tab

Absolutely. That was not what I had read as your request but it is much simpler if it meets your report specs.